/Engine/Source/Runtime/Engine/Classes/Materials/MaterialExpressionQualitySwitch.h
Recursively parse nodes outputing strata material in order to gather all the possible shading models used in a material graph output a Strata material.
virtual void GatherStrataMaterialInfo ( [FStrataMaterialInfo](API\Runtime\Engine\Engine\FStrataMaterialInfo) & StrataMaterialInfo, int32 OutputIndex )